What is your budget? If budget is not your priority then iPhone X is better phone . It has capability of recording 4k at 60fps best camera ,performance ,battery and all . But if you need android then go for Samsung Galaxy s8

The Galaxy S8 and S8+ will be capable of shooting and playing 4K video at 120 frames per second via an external monitor. But make sure that the 4K video should be included in Galaxy S8 playable 4K file formats such as 4K MP4, 4K AVI, 4K WMV, 4K MKV, you will fail to open some 4K files such as 4K MXF, 4K Prores, 4K XAVC/XAVC S on Galaxy S8.